Bug 35994

I have a HP/Compaq 8501w with a "ATI Technologies Inc M76 [Radeon Mobility
HD2600 Series]" graphics card.  It has a HDMI port on the side of it which I use to plug into a DVI monitor at home and work via a HDMI to DVI cable.

I was running linux 2.6.28 patched with

- bdd91b2b and fb939dfc (to fix 31339), and
- a0ae5864 (to fix 18564).

I upgraded to 2.6.38 and, while my monitor at home continues to work okay, my monitor at work now has flickering black lines and it cuts in and out to a black screen.  I did diffs of the kernel logs, xorg logs, and xrandr --verbose outputs, but nothing seemed to indicate any significant difference.

Finally, I

- checkout out the 2.6.38 kernel from git,
- reverted to bdd91b2b (the first version that had all the above patches), and
- discovered that it also had these problems, 

so I

- did a bisect on any changes that touched the radeon directory between that and 2.6.26 (cherry picking bdd91b2b, fb939dfc, and a0ae5864 as required), and
- this pointed to 48dfaaeb (drm/radeon/kms: remove new pll algo).

I then did some verification of this by

- attempting to revert 48dfaaeb on top of 2.6.38.

However, this failed as it was not clean and I was not sure of my corrections, so I instead

- reverted it on top of bdd91b2b (the first version that had all the above patches)

which produced a driver that worked fine with both monitors.

I presume this then means my monitor at work is having an issue with the pll settings the old new pll algorithm is generating.  I don't know what information would be helpful for resolving this though, so I'll just attach

- the kernel logs,
- the xorg logs, and
- the xrandr --verbose logs

for my original patched and working 2.6.36 kernel and the non-working 2.6.38 (although I couldn't see any significant differences in these).  Please let me know if there is any other information I can provide.

Thanks!  -Tyson